The Senate is on the verge of an extraordinary rebuke of Donald Trump’s foreign policy, underscoring a bipartisan willingness to encroach on the president’s powers as commander in chief.

From forcing Trump to impose sanctions on Russia to raising questions about his nuclear trigger finger, lawmakers are repeatedly asserting themselves in an area long dominated by the executive branch.

Story Continued Below

And now the fury is so great on Capitol Hill over the Saudi murder of Washington Post columnist Jamal Khashoggi — and the Trump administration’s tepid response — that senators are deliberating over whether to pull U.S. support for the Saudi-led coalition fighting in Yemen.

That senators have allowed the debate to even reach this stage is itself a reproach to Trump, who has downplayed evidence implicating the powerful Saudi crown prince suspected of masterminding the killing.

Trump has “forced members of the Senate to clarify that many of us continue to believe that we are a country that is safe and secure and prosperous when we put our values first and our interests second, not the other way around,” said Sen. Chris Coons (D-Del.), a member of the Foreign Relations Committee.

Sign up here for POLITICO Huddle

A daily play-by-play of congressional news in your inbox.

Email

By signing up you agree to receive email newsletters or alerts from POLITICO. You can unsubscribe at any time.

In fact, it’s Trump’s fellow Republicans who have often led the charge against his foreign policy — a sign that his nationalist views have gained little traction in his party’s upper rungs. And with Democrats taking control of the House next month, the Hill’s intrusion on foreign policy is likely to get even sharper.

Trump’s disdain for multilateralism, insults to U.S. allies and transactional approach to dealings with other countries have long alarmed top Republicans and Democrats alike. Trump’s attempts to gain favor with Russian President Vladimir Putin also upset many in both parties.

Signs that Congress would push back on Trump came within weeks of his taking office in 2017, when he proposed a budget that slashed funding for the State Department by a third. Republicans and Democrats dismissed the proposal and used their budget-setting power to protect funding for U.S. diplomacy.

Later in the year, Congress overwhelmingly passed a bill imposing sanctions on Russia over its interference in the 2016 presidential race. Unlike other such measures, the bill did not include a provision allowing the president to unilaterally waive sanctions, another rebuke of Trump, who reluctantly signed the veto-proof bill even as he said parts were unconstitutional.

The congressional reprimands of Trump also have taken other, often symbolic forms.

One example came when the GOP chairman of the Senate Foreign Relations Committee, Bob Corker of Tennessee, convened a hearing to examine the president’s authority to use nuclear weapons.

The hearing indicated that lawmakers did not trust Trump’s judgment, especially as he was exchanging heated rhetoric at the time with the nuclear-armed leader of North Korea.

Lawmakers on the left and right have frequently issued statements slamming the president for insulting U.S. allies in Europe and beyond. Behind the scenes, some lawmakers reach out directly to officials in offended governments to assure them of America’s continued support.

Lawmakers also have supported resolutions re-affirming U.S. support for the NATO military alliance. Earlier this year, a bipartisan group introduced legislation that would bar the president from quitting NATO without Senate consent.

Senate Republicans, including Corker and Sen. Pat Toomey (R-Pa.), pushed legislation earlier this year that would give Congress the authority to sign off on tariffs linked to national security, in a sign of their unease with Trump’s protectionist tendencies.

The congressional rebukes at times extend to foreign policy matters in which the president appears to take little interest.

Next week, the House is expected to easily pass a resolution declaring that the Myanmar military has been waging a genocide against Rohingya Muslims. The move amounts to a swipe at Secretary of State Mike Pompeo and an administration that refuses to take a stand on whether the anti-Rohingya campaign amounts to genocide.

Such moves “reflect a bipartisan majority of lawmakers who are fundamentally more internationalist and humanitarian in their global outlook than the president,” said Mariah Sixkiller, a former adviser to Democrat Steny Hoyer, the incoming House majority leader. “On the Republican side, some of that is true compassionate conservatism. That strain still exists.”

Jamie Fly, a former adviser to GOP Sen. Marco Rubio of Florida, noted: “There appear to be few repercussions with voters for Republican members who oppose the president on foreign policy – indicating perhaps that the Republican base may continue to support him in spite of his foreign policy views rather than because of them.”

The ongoing Congress-White House clash over Saudi Arabia encapsulates many concerns on the Hill about Trump, including his admiration for dictators, his vitriol toward journalists and a transactional approach to foreign affairs that puts little value on human rights.

Senators briefed this week by CIA director Gina Haspel say they are more convinced than ever that the Saudi crown prince, Mohammed bin Salman, orchestrated the murder of Khashoggi.

Khashoggi, who was living in the United States, had criticized the prince. He disappeared on Oct. 2 after entering the Saudi consulate in Istanbul, Turkey. The Saudi government admits he was killed by a hit squad waiting for him, but it denies the prince played a role.

Trump has argued that Saudi Arabia is too important to U.S. interests — keeping oil markets stable, containing Iran, and selling weapons — to anger by punishing the heir apparent.

But top lawmakers from both parties say they cannot let the crown prince off the hook. MBS, as he is also known, is in his 30s; if he reaches the throne he could rule for decades, and his record of squelching dissent so far has some lawmakers deeply alarmed about his future reign.

Sen. Lindsey Graham, a Republican from South Carolina who is a close Trump ally, has said he thinks MBS is “crazy.”

The discussion on the Hill about whether to keep supporting the Saudi-led war effort in Yemen, where millions of civilians face starvation, could still fall short of a vote to pull U.S. backing, but the mere fact that it’s happening is a sign of lawmakers’ discomfort with the Saudis — and Trump.

The White House, for its part, has insisted it’s not uniformly opposed to Congress taking a strong hand on foreign policy. Amid the congressional furor over Khashoggi’s killing, Trump vowed that he would “consider whatever ideas are presented to me, but only if they are consistent with the absolute security and safety of America.”

Despite all the maneuvering on Capitol Hill, the president retains tremendous influence over foreign policy. It is a power that scholars say has grown over time regardless of checks and balances provided in the Constitution. That’s especially the case when it comes to U.S. military actions, even though the Constitution gives Congress the power to declare war.

For all their concerted efforts under Trump, lawmakers have failed to devise a replacement for the 2001 law authorizing the use of military force abroad, a measure that has been used to justify military actions well beyond conflicts linked to the Sept. 11 attacks.

The moves in Congress could prove “an important attempt to take back some of the authorities and power the legislative branch has in shaping U.S. national security policy. But it’s too early to tell,” Brian Katulis of the left-leaning Center for American Progress wrote in an email.

Katulis also said Democrats, soon to take control of the House, may wind up viewing foreign policy as a wedge issue.

“If Democrats simply look at the things that will gain partisan advantage against Republicans,” he wrote, “they may be missing an opportunity to build bridges with some conservatives to check Trump.”